Without limiting the scope of the present invention, its background is described with reference to sand control completions, as an example.
It is well known in the subterranean well drilling and completion art that relatively fine particulate materials may be produced during the production of hydrocarbons from a well that traverses an unconsolidated or loosely consolidated formation. Numerous problems may occur as a result of the production of such particulate. For example, the particulate causes abrasive wear to components within the well, such as tubing, flow control devices, safety devices and the like. In addition, the particulate may partially or fully clog the well creating the need for an expensive workover. Also, if the particulate matter is produced to the surface, it must be removed from the hydrocarbon fluids using surface processing equipment.
One method for preventing the production of such particulate material is to gravel pack the well adjacent to the unconsolidated or loosely consolidated production interval. In a typical gravel pack completion, a sand control screen is lowered into the wellbore on a work string to a position proximate the desired production interval. A fluid slurry including a liquid carrier and a relatively coarse particulate material, such as sand, gravel or proppants, which are typically sized and graded and which are typically referred to herein as gravel, is then pumped down the work string and into the well annulus formed between the sand control screen and the perforated well casing or open hole production zone.
The liquid carrier either flows into the formation or returns to the surface by flowing through a wash pipe or both. In either case, the gravel is deposited around the sand control screen to form the gravel pack, which is highly permeable to the flow of hydrocarbon fluids but blocks the flow of the fine particulate materials carried in the hydrocarbon fluids. As such, gravel packs can successfully prevent the problems associated with the production of these particulate materials from the formation.
In other cases, it may be desirable to stimulate the formation by, for example, performing a formation fracturing and propping operation prior to or simultaneously with the gravel packing operation. This type of treatment process is commonly referred to as a frac pack. During this treatment process, hydraulic fractures are created in the hydrocarbon bearing formation, which increase the permeability of the formation adjacent the wellbore. According to conventional practice, a fracture fluid such as water, oil, oil/water emulsion, gelled water or gelled oil is pumped down the work string with sufficient volume and pressure to open multiple fractures in the production interval.
The fracture fluid may carry a suitable propping agent, such as sand, gravel or proppants, which are typically referred to herein as proppants, into the fractures for the purpose of holding the fractures open following the fracturing operation. In addition, these proppants are deposited around the sand control screen to form the gravel pack as described above. As such, frac packs can successfully enhance fluid production from the formation while also preventing the production of particulate materials from the formation.
Typically, downhole parameters such as pressure and temperature are obtained and recorded during such treatment processes with one or more downhole sensors. The information obtained by the sensors is later downloaded into surface or remote computers once the treatment operation is complete and the sensors have been tripped out of the wellbore. It has been found, however, that the quality of the treatment operation is evaluated only after such downhole sensors are brought to the surface. As such, the information obtained by the sensors is not supplied in a manner timely enough to allow modifications to the treatment operation.
Accordingly, a need has arisen for a communication system for transmitting data between downhole equipment and surface equipment that is operable to provide real-time information relating to parameters and conditions downhole such that modifications to a treatment operation may occur, if desired.